Which two statements about a Cisco Unified Communications Manager cluster are true? (Choose two.)

A.
A dedicated database publisher must always be collocated with a TFTP server.

B.
The TFTP server downloads configuration files, device loads or operating code, and ring types.

C.
Clusters of Cisco Unified CallManager servers may be added to the network, providing support for up to 24,000 users per cluster.

D.
A maximum of twelve servers may run the Cisco CallManager service, where devices can register.

E.
Cisco Unified Communications Manager is available on Windows-based operating systems (4.x versions), or Linux-based operating systems (5.x and 6.x versions).